Chandel, R. S.Chandel, Yamini2022-04-282022-04-282021-03-11https://krishikosh.egranth.ac.in/handle/1/5810183914The studies on biodiversity of phytophagous scarab beetles were conducted by using light traps and also by sampling them directly from their host trees at Sundernagar, Jogindernagar, Chailchowk, Pangna, Bagsaid and Janjehli in Mandi district of Himachal Pradesh from May-September 2019. At Sundernagar, Jogindernagar, Chailchowk and Pangna, Holotrichia longipennis Blanchard and Anomala lineatopennis Blanchard were recorded to be the predominant species. The relative abundance of H. longipennis varied from 13.45-23.36 per cent, and A. lineatopennis contributed to 14.19-24.41 per cent of total beetle catch. The predominant species at Bagsaid were Anomala dimidiata Hope and Anomala rufiventris Redtenbacher and these species comprised 14.90 and 14.60 per cent, respectively. Brahmina coriacea (Hope) and Brahmina flavosericea Brenske were found to be the other predominant species at Bagsaid and Janjehli, and their relative abundance was 14.23- 14.85 and 12.41-15.39 per cent at both these locations, respectively. The pooled analysis of data from six locations revealed that H. longipennis was the most predominant species comprising 16.31 per cent of total beetle catch on light trap. The Pielou’s evenness index was maximum at Pangna (J'= 0.86) and minimum at Sundernagar (J'= 0.73). The value of Shannon index (H') was computed to be maximum at Pangna (H'= 2.54), and minimum at Sundernagar (H'= 2.18). The Simpson’s index of diversity was maximum at Pangna (D= 0.90) and minimum at Chailchowk (D= 0.85). The Fisher plots indicated few common and more rare species at most of the locations. The Whittaker rank/ abundance curves showed greater evenness of scarab assemblage at Chailchowk and Pangna. The Beta diversity exhibited maximum similarity between Sundernagar and Chailchowk, whereas maximum dissimilarity between scarab communities was recorded between Jogindernagar and Janjehli. The survey of scarab beetles on host trees indicated the occurrence of 17 species on different fruit plants, forest trees, field crops, vegetables and ornamental plants. The five most leading species on different host plants were H. longipennis (23.13 %), B. coriacea (19.61%), B. flavosericea (12.43 %), Holotrichia sikkimensis Brenske (7.41%) and Maladera insanabilis (Brenske) (6.59 %). H. longipennis beetles exhibited distinct preference for rose, beans, toon, whereas B. coriacea and B. flavosericea beetles were collected only on apple in high hills. The value of Shannon index and Pielou’s evenness index was calculated to be maximum at Bagsaid (H'= 1.95) and Pangna (J'= 0.91), respectively. The Simpson’s index of diversity was computed to be maximum at Jogindernagar (D= 0.82). In the present study, five species viz. Asactapholis microsquamosa (Frey), Anomala variivestis Arrow, Anomala aureoflava Arrow, Holotrichia assamensis Brenske and Polyphylla fullo (Linnaeus) are new records from Himachal Pradesh. In potato, the tuber infestation of white grubs was very high (34.44 - 44.91 %). In peas, the plant mortality varied from 10.59 - 20.40 per cent. In garlic, 23.20 per cent bulbs were found to be infested by the grubs at RohandaEnglishThesis